Interesting experience with synthetic oil...

[weekendrider]

@xjwmx,
This may interest you.
http://www.upmpg.com/tech_articles/motoroil_viscosity/

The section under "Drawbacks of viscosity improving additives" explains why I start using oil after 900 - 1000 miles (imo)

You might also note the temp for viscosity is 210 degrees.
My motors are running above that. Soooooooo the higher weight/viscosity isn't really what the bottle says. The higher the temps the thinner the oil.

@XSLeo,
I really enjoyed the gravel analogy.
When I patch the drive I don't put in pea gravel. It simply won't hold. The next rain will have it all back in the creek.
If I use crusher run (everything under a certain screen size) the different sizes help hold it in place.

Thinking of it this way. Wouldn't different size molecules hold in the crevices of the cylinder walls better? Again these weren't built with tight tolerances the modern oils are developed for.

 

[XSLeo]

PHeller, I migt start at your local car parts stores. They often have a motorcycle section.
Next I might look at Wal Mart, they have a motor cycle/ ATV section, often they have a few oils.
After that any local independent dealers, then if all else fails dealers.
Weekender, dino oil the smaller particles might hold in the crevices better than the larger particles. Synth oil all the particles are small, uniform in size and shape. I think more of those will fit into and hold in better.
Patching the drive use crushed shale. Holds well and as you drive on it it crushes even more. When it rains this crushed shale acts like concrete as it dries, gets very hard. Not as easy on tires or your back when you crawl under the car.
I can remember years ago when Cadillac started having cam failures in there alloy block engines. They did some reasearch and found Chrysler had the same problem with there cam in the big magnum engines.
The trouble was 10w40 oil. The additive that was used to make a ten wieght oil act like a 40 wieght oil broke down in as few as 800 miles. Then the engines were running on 10w oil. Cams were burning up.
Mopar figured this out in the 60's, Cadillac did it in the 80's. Mopar just told folks not to use 10w40. In the General Motors case, they put it right in the owners manual. If you use 10w40 oil in the engine it invalidated the engine warranty.
I don't use 10w40 in anything I like. The newer Motorcycle 10w40 might be ok, they might have started using better additives.
Most oil people reccomend keeping oil temps in the 180-210 range, hotter won't hurt the oil much, say 240 just starts to burn the additives out.
Synth oils use less additives so they hold up better in hot engines.
Leo